1. Technical Field
The present disclosure relates to a radar apparatus for installation in a mobile unit including a vehicle.
2. Description of the Related Art
A radar apparatus is known in which reflected wave signals reflected by a target (hereinafter referred to as an object or target object) are received by an array antenna and the phase differences in the received signals received by the individual receive antennas are measured to estimate the direction in which the reflected wave signals from the object arrive over a wide angle range.
A conventional technique in which a radar apparatus which is capable of measurement over a wide angle range is installed in a mobile unit (a vehicle for example) and the relative speed of a nearby object with respect to the radar apparatus is detected is described in Japanese Unexamined Patent Application Publication No. 2010-043960, for instance.
A vehicle travel status detection device described in Japanese Unexamined Patent Application Publication No. 2010-043960 identifies a stationary object using radar apparatuses for lateral area monitoring installed in front of both sides of the vehicle. More specifically, the vehicle travel status detection device uses the azimuth φ and relative speed Vd0 of an electromagnetic wave reflection portion that is situated closest to the vehicle to correct the measured relative speed Vd0 of the electromagnetic wave reflection portion to Vd=Vd0×cos φ. The vehicle travel status detection device determines that a collection of electromagnetic wave reflection portions are a stationary object when the corrected relative speed Vd is equivalent to the detected value V0 of a speedometer provided in the vehicle. The value φ indicates the azimuth of an electromagnetic wave reflection portion, where the front direction of the vehicle is the reference (φ=0).